Apparatus for use in electric spot-welding



R. D. BELL APPARATUS FOR USE IN ELECTRIC SPOT WELDING June 27, 1933.

Filed Oct. 14, 1932 2 Sheets-Sheet 1 June 27, 1933. R. D. BELL APPARATUS FOR USE IN ELECTRIC SPOT WELDING 2` Sheets-Sheet 2 Filed 001:. 14, 1932 gym QJAM.

Patented June 27, 1933 UNITED STATES PATENT OFFICE,

ROBERT DAVIDSGN BELL, F DUNDEE, ANGUS, SCOTLAND Application filed October 14, 1932, Serial No. 637,828, and in. Great Britain October 16, 1931.

This invention relates to apparatus for use in electric spot-welding and has :tor an object the provision of a manually operable device suitable for use in dentistry7 watch and clock making, instrument making and other arts whereby metal articles and particularly but not necessarily small articles and more specilically those composed of stainless steel, may be electrically spot-welded. The apparatus lo may be employed without the use of a transformer, interrupter and switch it a battery forms the source of electric supply.

Brieiiy stated the present invention comprises electric spot welding apparatus of the l character described comprising a manually movable i'od mounted so that it is restrained to a predetermined path and provided with a pair of contacts each adapted to co-operate with a stationary contact electrically connected to a terminal of a battery or other electric supply and one of said stationary contacts forming the rest for the work to be spot welded and the other forming the Jfulcrum about which the rod turns.

My invention is shown by way of example in the accompanying drawings in which Figure 1 shows a perspective view of a spot welding machine according to the present invention. m Figure 2 shows a side view.

Figure 8 shows a plan view:

Figure 4 shows an end view with the handle removed for the sake of clearness and j Figure 5 shows an enlarged sectional dem tail view on the line V-V of Figure 2 of the pivotal connection between the rod frame and the plate on which it is mounted.

ln the machine shown in the drawings the rod 1 is manually operated by the handle 2 if and is adjustably mounted in the cross head 3 pivotally mounted at the tree extremities of the toggle arms i which are pivotally mounted on the cross member 5 attached by a j piece of insulating material 2% to the metal 4'" plate 6 which in turn is mounted on the insulated base 7, which tormsthe .top cover plate or" the battery 8. The position of the rod desired and is locked in set position by the 1 in the cross head 8 may be adjusted asv stud 21. The metal plate 6 is provided with openings 9 in register with the terminals 10 of the battery (or other source of supply if not obtained from a battery) and according to the voltage required is designed to be connected with one or other of said termi- 55 nals by means of the plug 11. This plate 6 is provided with a fixed Contact 12 adapted to make connection with the curved contact end of the rod 1 when the rod is in the position shown in the drawings. w

The terminal 18 of the battery has mounted thereon an angle arm 14 shown in dotted lines in Figures 2, 3 and 4. This arm carries a contact 15 which projects through an opening 17 in the insulated cover plate 7 The height 35 ot' this contact may be increased as shown in the drawings by theadditional contact piece 18. Itshould be understood that the contact piece 18 is not necessarily shaped as shown in the .drawings but, may have a blunt 'or a sharp 70 point. It may be bent or moulded into suitableV shape to accommodate the work being done. It is tapered and tits into a socket in 15 and is interchangeable with other terminals designed for particular work. The fixed 75 contact formed by the contact members, 15, 18 is adapted to form a rest or support for the work to be spotwelded., The point of the adjustable contact 19 mounted on the rod 1, is adapted to coact with the fixed contact members 15, 18 as shown in Figures 1 and 2 of the drawings. The position of the contact 19 on the rod 1 may be altered as required and the contact locked in set position by the stud 22. In use the work to be spot-welded is placed above and rests upon the point of the stationary contact member 18 and the rod 1 is manipulated so that its curved end rests on the stationary Contact 12 with its other ad- 90 justable contact 19 vertically or axially above the stationary contact member 18 on which the work is resting. The rod is now moved so that the contact 19 above the Work approaches the work, the other pair of contacts comprised of its curved end and the Contact 12 iorminga fulcrum. As soon as the contact 19 touches the work the spot-Weld is formed and immediately thereafter Vthe operator moves the rod further so that the contween the toggle arms l and themetalplate 6. As shown in Figure 5 l prefer to provide a spring- 20 in the pivotal connection betvveen the arms of the toggle frame 4, thus providing spring means tending to lift the Contact 19 ofi the Work to be spot'vvelded, against Which the handle is pressed down at the moment of Welding. Y

W hat I claim is 1. Electric spot `Welding prising a base, a manually movable rod mountedon said base, means for restraining thevmovement of said rod to a predetermined path and a pair of contactson said rod respe'ctively adapted to .co-operate With a pair of fixed contacts on said base connected to the terminals of an electric supply and one of said fixed contacts forming the rest for the Work to be spotWelded and the other formingthe fulcrumupon which said rod turns during itscmovement tothe spot Welding position.

2. Electric spot Welding apparatus comf prising a base, a frame hinged to said base, a

cross head hinged to the free extremity of said frame,.a manuallyinovablerod mounted intermediate of its ends 1n said cross head and Vadapted to be slidingly-adjusted therein in relation to the frame and a pair of contacts 'on said rod respectively adapted to co-operate with a pair of fixed contactson said base re-l spectively connected to the terminals of the electric supply and one of said fixed contacts forming the rest for the Work to be spot- Welded and the other forming the fulcrum upon which said rod turns during its'movement to the spot Welding position.

V8. Electric spot Welding apparatus comprising an insulated base, a metal plate mounted on' said base provided with openings therein in register with alternative terminals of one polarity of the electric supply, a plug adapted to `connect said' metal plate with one or the other of said terminals according to thevoltage required, a fixed Contact on said. plate, a manually movable rod mounted on` said metal plate, means for restraining the movement or said rod to a predetermined path and a pair of contacts on said rod respectively adaptedto co-operate With the fixed contact on said plate and a Vxed contact on said base connected to the terminal ,of the other polarity of the electric supply and one of said fixed contacts formapparatus com-k ing the rest for the Work to be spotWelded and the other forming the fulcrum upon Which said rod turns during its movement to the spot Welding position.

4. Electric spot Welding apparatus comprising an insulated base, a metal plate mounted on said base provided with openings therein in register With alternative terminals of one polarity of theelectric supply, a plug adapted to connect said metal plate With one or other of said terminals according to the voltage" required, a fixed contact on said plate, a frame hinged to said plate,across head hinged to the free extremity of said frame, a manually movable rod mounted intermediate of its ends in said cross head and adapted to be slidingly ad-. justed therein in relation to the frame and a pair of contacts on said rod respectively adapted to co-operate With the fixed Contact on said plate and a fixed contact on said base connected to the terminal of the other polarity of the electric supply and one of said fixed contacts forming the rest for the Work to be spotWelded and the other forming the fulcrum upon which said rod turns during its movement to the spot Welding position.

-5. Electric spot Welding apparatus comprising a base, a toggle lever systemmounted on said base, a manually movable rod mounted at the free end. of said toggle lever system and a pair of contacts on said rod respectively adapted tocco-operate With a pair of fixed contacts on said base connected to the terminals of an electric supply and one of said fixed contacts forming the rest for the Work to be spotwelded andthe other forming the fulcrum upon which said rod turns during its movement to the spot Welding position.

6. Electric spot Welding apparatus, com-` prisingan insulated base, a metal plate mounted onsaid base provided With openings therein in register With alternative terminals of one polarity of the electric supply, a plug adapted to connect said metal plate with one or otherV of said terminals according to the voltage required, a fixed contact on said plate, a toggle lever system mounted onk said plate, a cross head pivdted at the'free end of said toggle lever system, a manually movable rod mounted intermed-iate of its ends in said cross head and Y prising a base, a manually movable rod mounted on said base intermediate of its ends with a handle at one end and a downwardly curved free end, means for restraining the movement of said rod to a predetermined path, a slidingly adjustable contact at the handle end ofthe rod and a second contact at its curved end respectively adapted to co-op- Y erate with a pair of fixed contacts on said base connected to the terminals of the electric supply, the fixed contact co-acting with the handle contact of the rod forming the rest for the work to be spotwelded and the other fixed Contact forming the fulcrum upon which the rod turns during its movement to the spot welding position.

8. Electric spot welding apparatus comprising an insulated base, a metal plate mounted on said base provided with openings therein in register with alternative terminals of one polarity of the electric supply, a plug adapted to connect said metal plate with one or other of said terminals according to the voltage required, a fixed contact on said plate,

f a toggle lever system mounted on said plate,

a cross head fitted at the free end of said toggle lever system, a fixed Contact on said base connected to thel terminal of the other A polarity of the electric supply, a manually movable rod with a downwardly curved free end mounted insaid cross head and adapted to be slidingly adjusted therein in relation to the toggle lever system, a handle at the ystraight end of said rod, a slidingly adjustable contact at the handle end of said rod and a second contact at its curved end respectively adapted to co-operate with said fixed contacts on the base and plate, the fixed contact on the base forming the rest for the. work to be spotwelded and the fixed contact on the plate forming the fulcrum upon which the Contact at the curved end of the rod turns during the movement of the contact at the handle end of the rod to the spotwelding position.

9. Electric spot welding apparatus comprising an insulated base forming the cover plate of a battery a metal plate mounted on v said base provided with openings therein in register with alternative terminals of one polarity of the battery, a plug adapted toconnect said metal plate with one or the other of said terminals according to the voltage required, a fixed contact on said plate, a manually movable rod mounted on said metal plate, means for restraining the movement of said rod to a predetermined path and a pair of contacts on said rod respectively adapted to co-operate with the fixed contact on said plate and a fixed Contact on said base connected to the terminal of the other polarity of the battery and one of said xed contacts forming the rest for the work to be spotwelded and the other forming the fulcrum upon which said rod turns during its movement to the spot welding position.

10. Electric spot welding apparatus com-- prising an insulated base forming the cover plate of a battery, a metal platefmounted on said base provided with openings therein in register' with alternative terminals of one polarity of the battery, a plug adapted to connect said metal plate with one or the other of? said terminals according to the voltage required, a fixed Contact on said plate, a toggle lever system mounted onsaid plate, a cross head fitted at the free end of said toggle lever system, a fixed Contact on said base connected to the terminal of the other polarity of the battery, a manually movable rod with a downwardly curved free end mounted in said cross head and adapted to be slidingly adjusted therein in relation to the toggle lever system, a handle at the straight end of said rod, a. slidingly adjustable contact at the handle end of said rod and a second contact at its curved end respectively adapted to cooperate with said fixed contacts on the base and plate, the fixed contact on the base forming the rest for the work to be spotwelded and the fixed Contact on the plate forming thefulcrum upon which the contact at the curved end of the rod turns during the movement of the contact at the handle end of the rod to the spotwelding position.

11. Electric spot welding apparatus comprising abase, a toggle lever system mounted on said base, a manually movable rod mounted at the free end of said toggle lever system, a pair of contacts on said rod respectively adapted to co-operate with a pair vof fixed contacts on said base connected to the terminals of an electric supply and one of said fixed contacts forming the rest for the work to be spotwelded and the other forming the fulcrum upon which said rod turns during its movement to the spot welding position, and spring means in the pivotal connections between the arms of the toggle frame tending to lift the spot welding contact off the work to be spot welded resting thereon.

12. Electric spot-welding apparatus comprising a pivotal manually movable rod, a pair of contacts on said rod respectively arranged on each side of its pivotal point, one of said contacts being adapted in one position of the rod to make electrical connection with a source of electrical energy, and the n other of said contacts being adapted in the same position of the rod to make electrical Contact through the worlr to be welded with the same source of electrical energy to complete the circuit through the rod and the work. Y

13. Electric spot-welding apparatus comprising a pivotal movable rod, a pair of contacts on said rod respectively arranged on each side of its pivotal point, a pair of contacts contacting the other contact on the rod with its corresponding Contact on the terminal through the Work to be Welded.

In testimony whereof I have signed `my name to this specification.

ROBERT DAVIDSON BELL. 

